Liftmaster K15-48B9A1 Sprocket, 48B9T, 3/8"B
The LiftMaster K15-48B9A1 is a replacement sprocket marked 48B9T with a 3/8 inch bore. In a commercial door operator, the sprocket is part of the chain drive path and must line up correctly with the matching chain, shaft, and drive hardware. A worn sprocket can make a new chain wear quickly or cause a chain to climb, skip, or make excessive noise.
This is a precision fitment part. The tooth count, chain pitch, bore size, shaft fit, and location in the drive assembly all matter. The part is commonly listed for use with various LiftMaster commercial door operators, but exact fitment should be confirmed by the operator replacement parts diagram and original sprocket markings.
When replacing a sprocket, inspect chain stretch, shaft wear, keyway or set screw condition if applicable, and alignment. A chain and sprocket should work as a matched wear surface. If one is badly worn, the other may also need attention.
Compatible With
Common Compatible Models and Applications
- Select LiftMaster commercial door operators using a 48B9T sprocket with 3/8 inch bore
- Commercial door operator chain drive assemblies that specify K15-48B9A1
- Operator drive systems using the matching chain pitch and shaft size when confirmed by parts diagram
Additional Model Families to Verify
- Various LiftMaster mechanical and commercial door operator applications where the parts list calls for K15-48B9A1
- Older commercial operator drive assemblies only when the original sprocket marking and bore match
Important Compatibility Notes
- Confirm 48B9T sprocket marking and 3/8 inch bore.
- Match chain size and sprocket alignment.
- Do not substitute a sprocket based on tooth count alone.
Features and Specifications
| Feature / Specification | Details |
|---|
| Manufacturer | LiftMaster |
| Product Type | Drive sprocket |
| Part Number | K15-48B9A1 |
| Sprocket Marking | 48B9T |
| Bore | 3/8 inch |
| Application | Commercial door operator chain drive assembly |
| Compatible Operator Type | Select LiftMaster commercial door operators |
| Notes | Match tooth count, pitch, bore, and parts diagram |
Also Known As / Related Part Numbers
- K15-48B9A1
- 15-48B9A1
- 1548B9AXX
- 15482094
- 48B9T 3/8B
- 48B9X3/8
Technician Note
A new sprocket should run in line with the chain without side loading. If the chain rides up on the teeth, check chain pitch, shaft alignment, sprocket wear, and worn bearings before returning the operator to service.
Before Ordering
- Confirm the original sprocket marking is 48B9T.
- Measure or verify the 3/8 inch bore.
- Check the chain size and chain condition.
- Compare the sprocket location and mounting style with the parts diagram.
- Inspect bearings, shaft, and alignment before installation.
Professional Advisory
Commercial door operator drive parts are under load and can move unexpectedly if the operator is powered. Disconnect power and use proper lockout practices. Have a qualified technician service the operator if the drive system is damaged or misaligned.
Important Ordering Warnings
- A sprocket with the same bore may still have the wrong tooth count or chain pitch.
- A worn chain can quickly damage a new sprocket.
Product Questions and Answers
What does 48B9T mean on this sprocket?
It identifies the sprocket style/tooth specification used for matching the drive chain and operator assembly.
Is the bore size 3/8 inch?
Yes. This part is identified as a 48B9T sprocket with a 3/8 inch bore.
Can I replace only the sprocket?
Sometimes, but the chain, shaft, bearings, and alignment should be inspected because worn related parts can damage the new sprocket.
What operators use K15-48B9A1?
It is listed for various LiftMaster commercial door operators when the parts diagram calls for this sprocket.
Can I use a similar sprocket from another operator?
Do not substitute without confirming tooth count, pitch, bore, hub style, and alignment in the parts diagram.
